Re: vorticity anomalies

This is the correct approach.

Are your data 'global' and on a gaussian grid??

The uv2vrG on works on global grids. Are the latitudes S->N
as required?

printVarSummary( vrt )

shinnshinnwong@gmail.com wrote:
> Dear ncl users,
> I am now writing a code to extract 20-100 day 850hPa vorticity anomalies
> for mjo study. Below is the outline of my code:
>
> ihp = 2 ; bpf=>band pass filter
> nWgt = 201
> sigma = 1.0 ; Lanczos sigma
> fca = 1./100.
> fcb = 1./20.
> wgt = filwgts_lanczos (nWgt, ihp, fca, fcb, sigma )
>
> vrt = uv2vrG_Wrap(u,v) ; compute the vorticity from u and v
> xClmDay = clmDayTLL(vrt, yyyyddd) ; compute the daily climatology at
> each grid point
> xAnom = calcDayAnomTLL (vrt, yyyyddd, xClmDay) ; subtract the mean daily
> annual cycle from the raw daily data
> xAnom = wgt_runave_leftdim (xAnom, wgt, 0) ; apply filter
>
> The result seems to be different from what is expected. The region
> expected to have positive vorticity anomalies appears to be negative and
> vice versa.So Is this a feasible way of computing vorticity anomalies or
> have I made any mistakes? Any help and suggestion would be greatly
> appreciated. Thanks.
>
> Shinn
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> ncl-talk mailing list
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
_______________________________________________
ncl-talk mailing list
List instructions, subscriber options, unsubscribe:
http://mailman.ucar.edu/mailman/listinfo/ncl-talk
Received on Fri Feb 19 08:57:39 2010